Cut diamond



12153; 3(9, 1935. A, BAYARD! v 2,609,390

' cu'r DIAMOND Filed March 6, 1954 INVENTORJ Patented July 30, 1935 UNITED STATES PATENT QFFICE oU-T DIAMOND V Armand liayardi, New York, N. Y., assignor of two-fifths to Bayardi Brothers, Inc-,- NQW QIk;

N. n, a eorparati n of New York; two-fifths of New Jersey; and one-fifth to George A;

Schuetz, Maplewood, N 1.

Application March 6,1934, Serial No. 714,223

4 Claims. (ores-3'2) This invention relates generally to cut diamonds or precious stones and imitations thereof,

and more particularly to stones which are polygonal in plan, such as rectangular, trapezoidal, etc., one object of the invention being to provide a diamond or imitation thereof which shall have a novel and improved form including a unique relation of facets whereby a stone of given weight shall have novel and improved prismatic, light reflecting and light refracting characteristics of high degree to produce greater brilliancy than known cut gems of generally similar weightaancl character.

Another object is to provide-such a cut gem, particularly a diamond, which shall have a novel form and arrangement of facets on its-crown or bezel and on its base or pavilion, and the bezel. facets shall have a unique relation to the facets on the pavilion-to produce a large number of prismatic and light reflecting areas which'shall be capable of reflecting and refracting light raysin many different directions and substantially uni formly throughout the stone so that the gemshall have great and uniformbrilliancy and:

beautiful color and shall be devoid of dead spots.

Other objects areto provide astone of this character which can be out from the rough with a minimum of wastage of material whereby pro; duction of the stone shall be economical; to pro" vide such a stone which shall have its bezeljrand facets of such form that it shall have ahigh de gree of brilliancy even when the; pavilion facets 1 are enclosed in asetting or become coveredwith;

dirt or foreign matter; and to obtain other advantages and results as will be brought out by the following description.

Referring to the accompanyingdrawhig which corresponding andlike parts are designated by the same reference characters throughout.

the several views, V

Figure 1 is a top plan view of a-c'ut diamond Figure 6' is an enlargedfragr'nentary sc-heinatic 1 transversesectional view of aQportionof the pa- Figure 7 is a top plan View of another form er cut dialnbn'd embodying'theinvention Figure 8' is aside elevation of the diamond shown in Figure 7, and

Figures 9 and 10 are end elevations of the two ends of the diamond.

:Specificall'y describing the embodiment of the invention illustrated in Figures 1 to 6' inclusive, the diamond is polygonal in plan and as illus-i trated is rectangular. The diamond includes a; crown or bezel A and a pavilion or base B; The crown consists .of substantially a' cylindrical segment the sides-of thechordal plane of which form the girdle. C of the stone, while the pavilion B' is in; the form of a polyhedron-including four converging surfaces, the surfaces 13' constituting the sides of the pavilion, while the surfaces E constitute the ends of the pavilion. As shown, each side of the pavilion is' substantially in the form'of a trapezium or trapezoidyand' has one" side coincident with the girdle of the gem which is formed by the edges of the chordal plane of the cylindrically segmental crown. Each of the opposite sides D is approximately equal to the other,-while the sides E are also equal to each other, and said sides D and E are preferably symmetrical.

The crown A has a' plurality of longitudinal fiat facets I, the planes of which are angularly disposed to'ea'ch other, and' the side edges 2 of adjacent ones merge into-each other and'are approximately parallel't'o the girdle plane or extend in substantiallythe same direction as said'plane. The crown also has an inwardly inclined facet ear and coextensive with each end and angularly disposed to the facets I; Preferably the planes of'th'e' crown facets l betweedthe central facet- 4 and. the girdle are'disposed in different angular relations to the girdle plane varying from approximately fifty degrees to twenty degrees to the girdle plane; H

Two'opp'ositesides of the pavilion'are faceted, in the'present instancethe sidesD: These sides each have a plurality of longitudinal flat facets 5 in angularly disposed planes with their edges approximately parallel to thegirdle'plane or'e'xtending in the same general directionas the" side edges of the crown facets" I; The" other sides E of the pavilion'are preferably fiat; The facets '-aredisposed in different angular relations to the girdle plane varying from approximately sixty" eegr e's t'o thirty five degrees; while' me Sides El df the avilion are at aiii gl es of from thirty to fifty degrees to the gird-lereferably the transverse carver e Ofj th(? crown is" scream-any lessees -asei ni circle shown iii Figure' 3} and th 1 greatest thickness or the crown on a line normal to the girdle plane is substantially less than the greatest thickness of the pavilion from and on a line normal to the girdle plane.

A cut gem of this form has been found to have excellent light reflecting and refracting characteristics, and provides greater brilliancy for a given weight of stone than other out gems of generally similar weight and character, particularly gems of polygonal plan. Probably the the brilliant cut diamond has the greatest brilliancy of any of the cut stones, but it has been extremely difficult to cutv polygonal stones.

in such a way as to produce adequate brilliancy and color tone. The diamond of the invention takes advantage to a high degree of the great refractive and light dispersing characteristics of a diamond, and provides for repeated reflection of light within the stone and a high degree of refraction which causes ever-changing flashes of color to be observed in the crown of the stone.

Figures 4, 5 and 6 schematically illustrate the light reflecting and refracting characteristics of the' stone, These figures do not purport to be exactly correct in the delineation of the angles of refraction and reflection, but .are primarily for illustrative purposes. With reference to Figure 4, it will be observed that light rays F and G entering the crown 'of the stone through two different facets I will be first refracted and then reflected from the facets of one side D of the pavilion to the facets of the other side Dand then through other crown facets l where the light is again refracted. The light emerging from the crown is vari-colored due to refraction and it will be observed that many different rays of light may be reflected from many different angles so that brilliancy of the stone is of high degree. Some of the light rays will be reflected from the crown facets l onto the end facets E of the pavilion as shown in Figure 5, and the end facets 3 of the crown provide additional reflective surfaces to greatly increase the brilliancy of the stone, as in Figure 5. Two rays of light H and I are shown, one entering the central crown facet and the other entering one of the end facets 3 of the crown. The angular relationof the various facets, particularly the pavilion facets is such that most of the light entering the crown of the stone will strike the pavilion facets at angles greater than the critical angles of reflection of the diamond as shown in Figure 6, so that said rays will be reflected through the crown. The critical angles of the diamond are illustrated by dotted lines, and this critical angle is generally considered to be about twenty-four degrees.

A modification of the invention is shown in Figures 7 to 10 inclusive where the diamond is generally trapezoidal in plan. Also, the longitudinal edges of the crown facets l are located in planes at a slight angle to the plane of the girdle, as clearly shown in Figure 8, while the faceted sides K of the pavilion are in the form of trapeziums, and the flat sides L of the pavilion are approximately trapezoidal. The crown M of the stone is transversely arcuately curved but instead of being in the form of a cylindrical segment is in the form of approximately the segment of a cone. The light reflecting and refracting characteristics of this form of the stone are similar to those of the stone shown in Figures 1 to 6 inclusive.

Another advantage of the cut diamond embodying my invention isthat a minimum of waste isproduced in cutting the diamond from the rough so that production of the stone shall be economical. Furthermore, due to the many reflecting surfaces of the stone, the stone has a high degree of brilliancy even when the pavilion is set in a closed recess in the setting or becomes coated with dirt or foreign material. The Wide distribution or dispersion of light through the diamond provides a substantially uniform brilliancy throughout the stone and the stone therefore is devoid of dead spots which are common to many other types of polygonal cut stones. The large flat end surfaces E of the pavilion underlie substantially all of the crown facets I so that most of the light passing through the crown facets is reflected back through the crown rather than outwardly through the sides of the stone, and the large end facets 3 on the crown provide large areas for the entry of light into the stone and in combination with the large end surfaces E on the pavilion and the plurality of crown facets I provide for maximum light reflection and refraction to be viewed from the crown of the stone.

It will be understood by those skilled in the art that the specific contours of the stones illustrated are primarily for the purpose of illustrating the principles of the invention and that the invention may be embodied in stones of other shapes without departing from the spirit or scope of the invention.

Having thus described my invention, what I claim is:

1. A cut gem having a crown in the form of substantially acylindrical segment the sides of the chordal plane of which form the girdle of the gem, and a pavilion in the form of a polyhedron having the edges of its base coincident with the edges of the chordal plane of said cylindrically segmental crown and having four converging sides each in the general form of a sym-- metrical trapezoid opposite ones of which are equal, said crown having a plurality of longitudinal elongated flat facets the planes of which are angularly disposed to each other and the side edges of adjacent ones of which merge into each other and are parallel to said girdle, two opposite sides of said pavilion each having a plurality of longitudinal flat facets in angularly disposed planes and with their edges approximately parallel to the girdle, said crown having an inwardly inclined flat facet coextensive with each end thereof and angularly disposed to the firstmentioned facets, and the other sides of said pavilion beneath said flat end facets of the crown being flat.

2. The cut gem set forth in claim 1 wherein the greatest thickness of said crown from said girdle plane on a line normal thereto is substantially less than the greatest thickness of said pavilion from and on a line normal to said girdle plane, and the arc of curvature of said crown is substantially less than a semi-circle.

3. The cut gem set forth in claim 1 wherein the plane of the central crown facet is parallel to the girdle plane and the planes of the crown facets between said central facet and the girdle are disposed in different angular relations to the girdle plane varying from approximately 50 degrees to degrees, the end facets on the crown are at angles of from 50 to '70 degrees to said girdle plane, the facets on each of the faceted sides of saidpavilion are disposed in different angular relations to said girdle plane varying from approximately 60 degreesto 35 degrees and the flat sides of said pavilion are at angles of from 30 to 50 degrees to said girdle plane, and wherein the greatest thickness of said crown from and on a line normal to said girdle plane is substantially less than the greatest thickness of said pavilion from said girdle plane on a line normal thereto, and the arc of curvature of said crown is substantially less than a semi-circle.

4. A cut gem or imitation thereof including a crown and a pavilion and having a quadrilateral girdle plane, said crown and pavilion each having a plane surface at each end converging toward the other and joined by a plurality of plane elongated facets angularly disposed to one another, such elongated facets being also disposed so that the transverse section of the crown is approximately arcuately convex and the pavilion is approximately a polyhedron.

ARMAND BAYARDI. 

